Sweet Potato Muffins

Bahan-bahan (12 porsi)

• 2 -1/2 cups all-purpose flour
• 1 -1/2 teaspoons baking powder
• 1/2 teaspoon table salt
• 1/4 teaspoon baking soda
• 1/4 teaspoon ground nutmeg
• 1/4 cup buttermilk
• 1/3 cup milk
• 1 tablespoon sour cream
• 1/2 cup sweet potato puree (from 1 baked potato)
• 1 teaspoon vanilla extract
• 1 stick unsalted butter, room temperature
• 3/4 cup brown sugar
• 2 eggs
• 1/2 cup brown sugar
• 4 tbs. butter
• 1/2 cup sugar
• 2 teaspoons ground cinnamon